Michel Martinez | Universidad Católica de Colombia (original) (raw)
Papers by Michel Martinez
Disassembly for material recovery and environment protection is an increasingly important aspect ... more Disassembly for material recovery and environment protection is an increasingly important aspect in the manufacturing industry. Most of the present research works for disassembly focus on the generation of predictive optimal sequences. In fact, the disassembly process is particularly uncertain. Frequent incidents make a predetermined plan unrealistic. In this paper we present a new disassembly method in which the actual sequence of disassembly operations is progressively elaborated during the execution, in function of the real circumstances of the process. New concepts of disassembly operation and sequence equivalence are proposed together with a new representation of disassembly sequence. A decentralised and distributed control system based on a multi-agent technology is presented. The results of experimentation verify system flexibility and reactivity to unpredictable events, particularly disassembly operation failures
The concurrent design of a product and its manufacturing process requires a shared understanding ... more The concurrent design of a product and its manufacturing process requires a shared understanding of products and processes among many experts concerned with design and manufacturing. The objective of this paper is to provide an approach for the representation, integration and communication of different experts' viewpoints in the design and manufacturing phases. Firstly, we describe the problems related to concurrent design and current research works. Then we explain how, using the STEP standard, we can represent an integrated design and manufacturing model. As a case study, we consider the tracking of work-piece dimensions through all the different stages of product development, from design to machining. It is based on a model of machining tolerances based on a factory's machine-tool characterization. The chosen application case is a turning process. The model is validated by verification of the theoretical results in the case of machining several representative parts. Experiments point out the efficiency of our machining model. Finally, we present future developments of our integration work.
Page 1. Diptera. Chapter 10 553 Diptera Chapter 10 Marcela Skuhravá1, Michel Martinez2, Alain Roq... more Page 1. Diptera. Chapter 10 553 Diptera Chapter 10 Marcela Skuhravá1, Michel Martinez2, Alain Roques3 1 Bítovská 1227/9, 140 00 Praha 4, Czech Republic 2 INRA Centre de Biologie pour la Gestion des Popu-lations (CBGP ...
Proceedings of The Royal Society B: Biological Sciences, 2006
It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is enco... more It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is encoded by the ace-1 gene, distinct and divergent from the ace-2 gene, which performs this function in Drosophila. This is an unprecedented situation within the Diptera order because both ace genes derive from an old duplication and are present in most insects and arthropods. Nevertheless, Drosophila possesses only the ace-2 gene. Thus, a secondary loss occurred during the evolution of Diptera, implying a vital function switch from one gene (ace-1) to the other (ace-2). We sampled 78 species, representing 50 families (27% of the Dipteran families) spread over all major subdivisions of the Diptera, and looked for ace-1 and ace-2 by systematic PCR screening to determine which taxonomic groups within the Diptera have this gene change. We show that this loss probably extends to all true flies (or Cyclorrhapha), a large monophyletic group of the Diptera. We also show that ace-2 plays a non-detectable role in the synaptic AChE in a lower Diptera species, suggesting that it has non-synaptic functions. A relative molecular evolution rate test showed that the intensity of purifying selection on ace-2 sequences is constant across the Diptera, irrespective of the presence or absence of ace-1, confirming the evolutionary importance of non-synaptic functions for this gene. We discuss the evolutionary scenarios for the takeover of ace-2 and the loss of ace-1, taking into account our limited knowledge of non-synaptic functions of ace genes and some specific adaptations of true flies.
Disassembly for material recovery and environment protection is an increasingly important aspect ... more Disassembly for material recovery and environment protection is an increasingly important aspect in the manufacturing industry. Most of the present research works for disassembly focus on the generation of predictive optimal sequences. In fact, the disassembly process is particularly uncertain. Frequent incidents make a predetermined plan unrealistic. In this paper we present a new disassembly method in which the actual sequence of disassembly operations is progressively elaborated during the execution, in function of the real circumstances of the process. New concepts of disassembly operation and sequence equivalence are proposed together with a new representation of disassembly sequence. A decentralised and distributed control system based on a multi-agent technology is presented. The results of experimentation verify system flexibility and reactivity to unpredictable events, particularly disassembly operation failures
The concurrent design of a product and its manufacturing process requires a shared understanding ... more The concurrent design of a product and its manufacturing process requires a shared understanding of products and processes among many experts concerned with design and manufacturing. The objective of this paper is to provide an approach for the representation, integration and communication of different experts' viewpoints in the design and manufacturing phases. Firstly, we describe the problems related to concurrent design and current research works. Then we explain how, using the STEP standard, we can represent an integrated design and manufacturing model. As a case study, we consider the tracking of work-piece dimensions through all the different stages of product development, from design to machining. It is based on a model of machining tolerances based on a factory's machine-tool characterization. The chosen application case is a turning process. The model is validated by verification of the theoretical results in the case of machining several representative parts. Experiments point out the efficiency of our machining model. Finally, we present future developments of our integration work.
Page 1. Diptera. Chapter 10 553 Diptera Chapter 10 Marcela Skuhravá1, Michel Martinez2, Alain Roq... more Page 1. Diptera. Chapter 10 553 Diptera Chapter 10 Marcela Skuhravá1, Michel Martinez2, Alain Roques3 1 Bítovská 1227/9, 140 00 Praha 4, Czech Republic 2 INRA Centre de Biologie pour la Gestion des Popu-lations (CBGP ...
Proceedings of The Royal Society B: Biological Sciences, 2006
It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is enco... more It has recently been reported that the synaptic acetylcholinesterase (AChE) in mosquitoes is encoded by the ace-1 gene, distinct and divergent from the ace-2 gene, which performs this function in Drosophila. This is an unprecedented situation within the Diptera order because both ace genes derive from an old duplication and are present in most insects and arthropods. Nevertheless, Drosophila possesses only the ace-2 gene. Thus, a secondary loss occurred during the evolution of Diptera, implying a vital function switch from one gene (ace-1) to the other (ace-2). We sampled 78 species, representing 50 families (27% of the Dipteran families) spread over all major subdivisions of the Diptera, and looked for ace-1 and ace-2 by systematic PCR screening to determine which taxonomic groups within the Diptera have this gene change. We show that this loss probably extends to all true flies (or Cyclorrhapha), a large monophyletic group of the Diptera. We also show that ace-2 plays a non-detectable role in the synaptic AChE in a lower Diptera species, suggesting that it has non-synaptic functions. A relative molecular evolution rate test showed that the intensity of purifying selection on ace-2 sequences is constant across the Diptera, irrespective of the presence or absence of ace-1, confirming the evolutionary importance of non-synaptic functions for this gene. We discuss the evolutionary scenarios for the takeover of ace-2 and the loss of ace-1, taking into account our limited knowledge of non-synaptic functions of ace genes and some specific adaptations of true flies.